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AP

French police stand outside a house in a residential area in Talloires, French Alps, Tuesday, Feb. 18, 2014, as part of the continuing investigation into the grisly shooting deaths of a British-Iraqi man and three others nearly 18-months ago.

Police in France have made a second arrest after discovering a weapons cache in connection with their investigation into the killings of a British-Iraqi man, his wife and two others in the French Alps in September 2012.

On Tuesday a security guard, 48, was arrested over the killings. A sweep of his home turned up guns, grnades and mortars in his home. His roommate has also now been detained, the Associated Press reports.

The inquiry stems from an incident in September 2012 in which Saad al-Hilli, a prominent Iraqi man, his wife, an elderly relative and a French cyclist were gunned down near Lake Annecy in the Alps. Authorities are looking into another probe around the two men linked to weapons trafficking.

The identities of the two men have not been revealed as authorities say no link has been made yet between either of them and the chilling murders.